Hi juzhe,
I also thought it’s related to commutive firstly.
Following things make me to do the removal:
1. No tests fails in regression
2. When I write if (a == 2) and if (2 == a), the results are same
3. The vec_duplicate operand is the 5th operand in both cmp and eqne
patterns. I think they are equal.
From: 钟居哲 <juzhe.zh...@rivai.ai>
Sent: 2024年3月1日 15:24
To: Demin Han <demin....@starfivetech.com>; gcc-patches
<gcc-patches@gcc.gnu.org>
Cc: kito.cheng <kito.ch...@gmail.com>; Li, Pan2 <pan2...@intel.com>;
jeffreyalaw <jeffreya...@gmail.com>; Robin Dapp <rdapp....@gmail.com>
Subject: Re:[PATCH 1/5] RISC-V: Remove float vector eqne pattern
Hello, han. Thanks for trying to optimize the codes.
But I believe those vector-scalar patterns (eq/ne) you remove in this patch are
necessary.
This is the story:
1. For commutative RTL code in GCC like plus, eq, ne, ... etc,
we known in semantic Both (eq: (reg) (vec_duplicate ... ) and (eq:
(vec_duplicate ... ) (reg)) are right.
However, GCC prefer this order as I remembered - (eq: (vec_duplicate ... )
(reg)).
2. Before this patch, the order of the comparison as follows (take eq and lt as
an example):
1). (eq: (vec_duplicate ... ) (reg)) --> commutative
2). (lt: (reg) (vec_duplicate ... ) --> non-commutative
These patterns order are different.
So, you see we have dedicated patterns (seems duplicate patterns) for
vector-scalar eq/ne, whereas, we unify eq/ne into other comparisons for
vector-vector instructions.
If we unify eq/ne into other comparisons for vector-scalar instructions
(like your patch does), we will end up have:
(eq: (reg) (vec_duplicate ... ) [after this patch] instead of (eq:
(vec_duplicate ... ) (reg)) [Before this patch].
So, I think this patch may not be right.
I may be wrong, Robin/Jerff/kito feel free to correct me if I am wrong.
------------------ Original ------------------
From:
"demin.han"<demin....@starfivetech.com<mailto:demin....@starfivetech.com>>;
Date: Fri, Mar 1, 2024 02:27 PM
To: "gcc-patches"<gcc-patches@gcc.gnu.org<mailto:gcc-patches@gcc.gnu.org>>;
Cc: "juzhe.zhong"<juzhe.zh...@rivai.ai<mailto:juzhe.zh...@rivai.ai>>;
"kito.cheng"<kito.ch...@gmail.com<mailto:kito.ch...@gmail.com>>; "Li,
Pan2"<pan2...@intel.com<mailto:pan2...@intel.com>>;
"jeffreyalaw"<jeffreya...@gmail.com<mailto:jeffreya...@gmail.com>>;
Subject: [PATCH 1/5] RISC-V: Remove float vector eqne pattern
We can unify eqne and other comparison operations.
Tested on RV32 and RV64
gcc/ChangeLog:
* config/riscv/riscv-vector-builtins-bases.cc: Remove eqne cond
* config/riscv/vector.md (@pred_eqne<mode>_scalar): Remove patterns
(*pred_eqne<mode>_scalar_merge_tie_mask): Ditto
(*pred_eqne<mode>_scalar): Ditto
(*pred_eqne<mode>_scalar_narrow): Ditto
Signed-off-by: demin.han
<demin....@starfivetech.com<mailto:demin....@starfivetech.com>>
---
.../riscv/riscv-vector-builtins-bases.cc | 4 -
gcc/config/riscv/vector.md | 86 -------------------
2 files changed, 90 deletions(-)
diff --git a/gcc/config/riscv/riscv-vector-builtins-bases.cc
b/gcc/config/riscv/riscv-vector-builtins-bases.cc
index b6f6e4ff37e..d414721ede8 100644
--- a/gcc/config/riscv/riscv-vector-builtins-bases.cc
+++ b/gcc/config/riscv/riscv-vector-builtins-bases.cc
@@ -1420,10 +1420,6 @@ public:
switch (e.op_info->op)
{
case OP_TYPE_vf: {
- if (CODE == EQ || CODE == NE)
- return e.use_compare_insn (CODE, code_for_pred_eqne_scalar (
- e.vector_mode ()));
- else
return e.use_compare_insn (CODE, code_for_pred_cmp_scalar (
e.vector_mode ()));
}
diff --git a/gcc/config/riscv/vector.md b/gcc/config/riscv/vector.md
index ab6e099852d..9210d7c28ad 100644
--- a/gcc/config/riscv/vector.md
+++ b/gcc/config/riscv/vector.md
@@ -7520,92 +7520,6 @@ (define_insn "*pred_cmp<mode>_scalar_narrow"
(set_attr "mode" "<MODE>")
(set_attr "spec_restriction" "none,thv,thv,none,none")])
-(define_expand "@pred_eqne<mode>_scalar"
- [(set (match_operand:<VM> 0 "register_operand")
- (if_then_else:<VM>
- (unspec:<VM>
- [(match_operand:<VM> 1 "vector_mask_operand")
- (match_operand 6 "vector_length_operand")
- (match_operand 7 "const_int_operand")
- (match_operand 8 "const_int_operand")
- (reg:SI VL_REGNUM)
- (reg:SI VTYPE_REGNUM)] UNSPEC_VPREDICATE)
- (match_operator:<VM> 3 "equality_operator"
- [(vec_duplicate:V_VLSF
- (match_operand:<VEL> 5 "register_operand"))
- (match_operand:V_VLSF 4 "register_operand")])
- (match_operand:<VM> 2 "vector_merge_operand")))]
- "TARGET_VECTOR"
- {})
-
-(define_insn "*pred_eqne<mode>_scalar_merge_tie_mask"
- [(set (match_operand:<VM> 0 "register_operand" "=vm")
- (if_then_else:<VM>
- (unspec:<VM>
- [(match_operand:<VM> 1 "register_operand" " 0")
- (match_operand 5 "vector_length_operand" " rK")
- (match_operand 6 "const_int_operand" " i")
- (match_operand 7 "const_int_operand" " i")
- (reg:SI VL_REGNUM)
- (reg:SI VTYPE_REGNUM)] UNSPEC_VPREDICATE)
- (match_operator:<VM> 2 "equality_operator"
- [(vec_duplicate:V_VLSF
- (match_operand:<VEL> 4 "register_operand" " f"))
- (match_operand:V_VLSF 3 "register_operand" " vr")])
- (match_dup 1)))]
- "TARGET_VECTOR"
- "vmf%B2.vf\t%0,%3,%4,v0.t"
- [(set_attr "type" "vfcmp")
- (set_attr "mode" "<MODE>")
- (set_attr "merge_op_idx" "1")
- (set_attr "vl_op_idx" "5")
- (set (attr "ma") (symbol_ref "riscv_vector::get_ma(operands[6])"))
- (set (attr "avl_type_idx") (const_int 7))])
-
-;; We don't use early-clobber for LMUL <= 1 to get better codegen.
-(define_insn "*pred_eqne<mode>_scalar"
- [(set (match_operand:<VM> 0 "register_operand" "=vr, vr,
&vr, &vr")
- (if_then_else:<VM>
- (unspec:<VM>
- [(match_operand:<VM> 1 "vector_mask_operand"
"vmWc1,vmWc1,vmWc1,vmWc1")
- (match_operand 6 "vector_length_operand" " rK, rK, rK,
rK")
- (match_operand 7 "const_int_operand" " i, i, i,
i")
- (match_operand 8 "const_int_operand" " i, i, i,
i")
- (reg:SI VL_REGNUM)
- (reg:SI VTYPE_REGNUM)] UNSPEC_VPREDICATE)
- (match_operator:<VM> 3 "equality_operator"
- [(vec_duplicate:V_VLSF
- (match_operand:<VEL> 5 "register_operand" " f, f, f,
f"))
- (match_operand:V_VLSF 4 "register_operand" " vr, vr, vr,
vr")])
- (match_operand:<VM> 2 "vector_merge_operand" " vu, 0, vu,
0")))]
- "TARGET_VECTOR && riscv_vector::cmp_lmul_le_one (<MODE>mode)"
- "vmf%B3.vf\t%0,%4,%5%p1"
- [(set_attr "type" "vfcmp")
- (set_attr "mode" "<MODE>")
- (set_attr "spec_restriction" "thv,thv,rvv,rvv")])
-
-;; We use early-clobber for source LMUL > dest LMUL.
-(define_insn "*pred_eqne<mode>_scalar_narrow"
- [(set (match_operand:<VM> 0 "register_operand" "=vm, vr,
vr, &vr, &vr")
- (if_then_else:<VM>
- (unspec:<VM>
- [(match_operand:<VM> 1 "vector_mask_operand" "
0,vmWc1,vmWc1,vmWc1,vmWc1")
- (match_operand 6 "vector_length_operand" " rK, rK, rK,
rK, rK")
- (match_operand 7 "const_int_operand" " i, i, i,
i, i")
- (match_operand 8 "const_int_operand" " i, i, i,
i, i")
- (reg:SI VL_REGNUM)
- (reg:SI VTYPE_REGNUM)] UNSPEC_VPREDICATE)
- (match_operator:<VM> 3 "equality_operator"
- [(vec_duplicate:V_VLSF
- (match_operand:<VEL> 5 "register_operand" " f, f, f,
f, f"))
- (match_operand:V_VLSF 4 "register_operand" " vr, 0, 0,
vr, vr")])
- (match_operand:<VM> 2 "vector_merge_operand" " vu, vu, 0,
vu, 0")))]
- "TARGET_VECTOR && riscv_vector::cmp_lmul_gt_one (<MODE>mode)"
- "vmf%B3.vf\t%0,%4,%5%p1"
- [(set_attr "type" "vfcmp")
- (set_attr "mode" "<MODE>")
- (set_attr "spec_restriction" "none,thv,thv,none,none")])
-
;;
-------------------------------------------------------------------------------
;; ---- Predicated floating-point merge
;;
-------------------------------------------------------------------------------
--
2.43.2
